Spray painting apparatus including a workholder, mask and aligning means therefor



Dec. 5, 1967 c. G. MARTIN 3,356,069

SPRAY PAINTING APPARATUS INCLUDING A WORKHOLDER, MASK AND ALIGNING MEANSTHEREFOR Filed May 16, 1966 2 Sheets-Sheet 1 MASK Dec. 5, 1967 c. G.MARTIN SPRAY PAINTING APPARATUS INCLUDING A WORKHOIJDER,

AND ALIGNING MEANS THEREFOR 2 Sheets-Sheet 2 Filed May 16, 1966 FOOTPEDAL INVENTOR. CLYDE G. MARTIN Wham United States Patent C) 3,356,069SPRAY PAINTING APPARATUS INCLUDING A WORKHOLDER, MASK AND ALIGNING MEANSTHEREFQR Clyde G. Martin, Toledo, Ghio, assignor to Conforming lllfitrixCorporation, Toledo, Ohio, a corporation of Filed May 16, 1966, Ser. No.550,458 9 Claims. (Cl. 118-301) The invention relates to a multiplespray painting fixture for holding two or more interchangeable spraymasks to be used in painting an article in two or more colors.

When it is necessary to paint a particular area of an article in amanufacturing operation, it is customary to employ a mask that fits thearticle closely, exposes the area to be painted and covers the remainderof the article. In the production of large quantities of articles thatare so painted it is desirable to employ a fixture in which the spraymask and a work holder are mounted for relative movement so that thearticle to be painted can be positioned precisely on the Work holder andthen can be brought into proper engagement with the mask by moving thework holder toward the mask.

When it is necessary to apply different colors to two or more areas onthe surface of an article, the operation of painting the article is morecumbersome because it is necessary to employ a separate mask to defineeach area to which a particular color is to be applied. When a spraymask is used to apply paint of one color to an article and is thenreplaced by another spray mask for applying paint of another color to adifferent area on the article, it is necessary to position each maskwith great precision to insure that in each painting operation. thepaint will be applied to the desired area. The operation of preciselypositioning a mask on a fixture is most difiicult in the case of a largemask which is used for applying paint to a relatively large area.

The principal object of the invention is to provide a spray paintingfixture having a single work holder and having mountings for supportinga plurality of spray masks, which is of improved design to permit eachof the spray masks selectively to be brought quickly into a preciseposition so that the work held by the work holder can be engaged withthe mask for spray painting. More specific objects and advantages areapparent from the following description, in which reference is had tothe.

accompanying drawings illustrating a preferred embodiment of theinvention. In the drawings:

FIG. 1 is a side elevation of a preferred form of device embodying theinvention.

FIG. 2 is an end elevation,

FIG. 3 is an exploded end elevation of the mounting for holding a mask.

FIG. 4 is a perspective view of a mask.

FIG. 5 is a perspective view of the mounting for holding a mask.

FIG. 6 is a diagram of the air piping and controls.

These specific drawings and the specific description that follows areintended to disclose and illustrate and not to limit the invention.

The multiple spray painting fixture shown in the draw ings is supportedupon two leg members 10, each of which rides upon two casters 11. Eachof the leg members 10 consists of an X-shaped frame made by weldingpieces of angle and including a horizontal angle 12 welded across thetop of the leg member. The base portion of the fixture includes aninverted channel 13 beneath the ends of which are welded two transverseplates 14. Each of these transverse plates 14 is bolted to thehorizontal ment which might otherwise occur because of slight bend angle12 which forms the top portion of one of the leg members 10.

Secured to and depending from the channel 13 are two air cylinders 15.The pistons 16 which extend upward from the air cylinders 15 support awork holder 17 that carries a work-supporting platform 18 provided withwork-locating members which in the illustrated embodiment consist offour angles 13. Additional locating members may be provided whennecessary to fit the article to be painted, so that when the article isplaced upon the platform 18 it is held in a precise position. Theplatform 18 remains horizontal at all times, so that an article placedupon the platform is held in position by gravity.

Secured to and depending from the work holder 17 are a pair of racks 20.The racks 20 mesh with a pair of gears 21 fixed on the two ends of ashaft 22 which is mounted in two bearings 23 each of which is secured toa plate 24 welded across the bottom of the inverted channel 13. Thisarrangement of racks and gears keeps the work holder 17 horizontal andprevents either of the piston rods 16 from moving faster than the otherpiston rod.

The assembly that carries the spray masks includes a pair of discs 25. Abearing 26 is secured to the center of each of the discs 25, and eachdisc is pivoted by means of the bearing 26 upon a stud 27 which isprovided with a flat head 28 and is secured in a bracket 29 welded ontop of the inverted channel 13.

Bolted to the inner face of each of the discs 25 are three guideways 30,each of which is provided on its inner side with a longitudinallyextending groove 31 (FIGS. 3 and 5 Each of the guideways 30 is connectedat one end by means of an angle 32 to a guideway on the opposite disc25. The three angles 32 which connect the three pairs of guideways 30.also form the connection between the two discs 25 to produce a singlemask carrying assembly. Each angle 32 with its two guideways 30constitutes a mounting for supporting a spray mask.

Each spray mask 33 (FIG. 4) consists of a relatively shallow channelincluding a front wall 34 to which are secured a pair of handles 35, anda rear wall 36 which has a portion cut away at each end to permit theedges at the two ends of the channel to be slid into the grooves 31 ofthe guideways 30. At the front end of each guideway 30, a portion of theguideway above the groove is cut away to leave an exposed ledge 37, sothat the rear corners of the mask 33 can be dropped onto the ledges 37to place the mask in a position such that it can be slid readily intothe grooves 31.

Two blocks 38 are welded upon each of the angles 32, and a bushing 39extends through each of the blocks 38. When a mask is mounted in theguideways 30 in proper position for painting, each bushing 39 and acorresponding hole 40 in the angle 32 are in alignment with a hole 41 inthe mask 33. In order to secure the mask in position, a pin 42 isinserted by hand through each bushing 39 and the corresponding holes 40and 41.

Also secured to each mask 33 are two plates 43, through each of whichextends a relatively large bushing 44. The two bushings 44 constitutealigning apertures for receiving two aligning pins 45 which are mountedon the ends of the work holder 17 and which, when the work holder israised by the air cylinders 15, enter the bushings 44 through relativelylarge holes provided in the mask 33 below the bushings 44.

The entry of the aligning pins 45 into the bushings 44 on the spray mask33 performs the final precise alignment of the spray mask with the workon the platform 18 carried by the work holder 17. The final precisealignment performed by the aligning pins 45 corrects any misalign-Patented Dec. 5, 1967 ing or distortion of the assembly which carriesthe spray mask.

In accordance with the present invention it has been discovered thatbefore the work holder is brought into engagement with a spray maskcarried by the pivotally mounted assembly, causing the aligning pins toengage the aligning apertures in the spray mask, it is desirable toperform a rather precise preliminary alignment of the pivotally mountedassembly which carries the spray mask. A considerable amount of forcemust be employed to move the relatively heavy work holder intoengagement with the spray mask, and it has been found that without arather precise preliminary alignment of the pivotally mounted assemblyto bring the spray mask into a substantially correct position, a slightmisalignment of the spray mask may cause the mask to be damaged when thealigning pins attempt to enter the aligning apertures in the spray mask.Accordingly, an important feature of the present invention consists inthe provision of at least one plot in pin which is slidably mounted onthe base for longitudinal movement, and the provision of a plurality ofapertures in the pivotally mounted assembly, each aperture being locatedto receive a pilot pin when the assembly is in an angular position inwhich an aligning aperture in a spray mask carried by the assembly issubtantially aligned with the corresponding aligning pin carried by thework holder.

In the specific embodiment shown in the drawings, each of the discs 25is provided with three aligning apertures 46 for receiving a pilot pin47 that is slidable in a bore provided in a block 48 secured to the sideof the channel 13. Each of the pilot pins 47 forms an extension of thepiston of an air cylinder 49 which also is secured to the side of thechannel 13. Whenever each of the pilot pins 47 is engaged in one of theapertures 46, one of the spray masks carried by the pivotally mountedassembly is properly located in a position vertically above the workholder 17.

Each air cylinder 49 provides a separate drive for slidably moving thepilot pin, so that the pilot pin may be first engaged with one of theapertures 46, and the work holder then may be moved to engage thealigning pins 45 with the corresponding apertures in the spray mask.

As shown in FIG. 6, compressed air may be supplied to the system throughtwo separate regulators 50 and 51 which may be set to maintain twodifferent pressures. Compressed air is supplied through the regulator 51to a foot pedal-operated valve 52. The valve 52 has two operatingpositions, in one of which it admits compressed air from the regulator51 to the spaces below the pistons in the air cylinders 15. In its otheroperating position, the valve 52 shuts oif the supply of compressed airfrom the regulator 51 and vents the spaces below the pistons of the aircylinders to the atmosphere in order to permit the work holder 17 tomove downward under the influence of gravity.

Compressed air from the regulator 51 also is supplied to a footpedal-operated pilot valve 53. The pilot valve 53 has two operatingpositions, in one of which it supplies compressed air from the regulator51 to a plenum chamber 54, and in the other of which it vents the plenumchamber 54 to the atmosphere. The pressure in the plenum chamber 54controls a spring-biased reversing valve 55 which is connected to theregulator 50. The reversing valve 55 has two operating positions, one ofwhich it assumes when compressed air from the regulator 51 is suppliedto the plenum chamber 54, and the other of which it assumes when theplenum chamber 54, is vented to the atmosphere. In one of the operatingpositions of the reversing valve 55, the spaces at the left side of thepistons in the air cylinders 49 are supplied with compressed air fromthe regulator 50 and the spaces at the right side of the pistons arevented to the atmosphere. In the other position of the reversing valve55, the spaces at the right side of the pistons in the air cylinders 49are supplied with compressed air from the regulator 50 and the spaces atthe left side of the pistons are vented to the atmosphere.

In the operation of the device illustrated in the drawings, the operatorfirst places the article to be painted upon the platform 18 while thework holder 17 is in its lower most position. At this time the pivotallymounted assembly is so positioned that the desired one of the masks islocated vertically above the platform 18, and the air cylinders 49 areoperated by means of the pilot valve 53 to bring the pins 47 intoengagement with the proper apertures 4-6. The operator then operates thevalve 52 by means of the foot pedal to supply compressed air to thespaces below the pistons in the air cylinders 15, thus raising the workholder 17 until the aligning pins 45 enter the aligning aperturesprovided by the bushings 44 on the mask 33. When the work holder 17 isfully raised, the mask 33 is properly aligned with the work, and thework is tightly engaged with the mask. The operator then uses a spraygun to spray paint through the mask so as to apply paint to the properarea of the article.

When this painting operation has been completed, the operator places thevalve 52 in its other operating position by means of the foot pedal,thus venting the spaces below the pistons in the air cylinders 15 to theatmosphere and permitting the work holder to settle into its lowermostposition. He also places the pilot valve 53 in position to retract thepilot pins 47. Then the operator grasps hand rails 56 which are providedon the discs 25 and rotates the mask-carrying assembly to bring adifferent mask into a position vertically above the work holder 17. Thepilot valve 53 is also reactuated by releasing the foot pedal to bringthe pilot pins 47 into engagement with the pro-per apertures 46.

The work holder 17 is then raised in the manner previously described,and paint of another color is applied to the proper area of the article.Then if paint of a third color is to be applied, the illustrated devicecan be operated again in the manner described, to permit a third mask 33to be employed in a third painting operation.

The pilot pins 47 are operated by the relatively small air cylinders 49with a short stroke and with relatively little force. Thus the pilotpins 47 can be manipulated quickly and easily in performing thepreliminary aligning operation. At the same time the preliminaryalignment performed by the pilot pins 47 is precise, and it has beenfound that this preliminary alignment enables the aligning pins 45 toenter the bushings 44 provided on the spray mask to correct anydeformation of the structure without any danger of damaging the spraymask.

The embodiment illustrated in the drawings may be varied when necessaryto meet various requirements.

Having described the invention, I claim:

1. A multiple spray painting fixture comprising a base, an assemblywhich is pivotally mounted on the base and which carries a plurality ofmountings for supporting a plurality of spray masks in positions thatare angularly displaced from one another, a work holder which isslidably mounted on the base and which carries an aligning pin extendingin the direction of the sliding movement of the work holder for engagingan aligning aperture in a spray mask carried by the pivotally mountedassembly, in order to align the mask with work which is to be spraypainted through the mask and which is held on the work holder, and apilot pin which is slidably mounted on the base for longitudinalmovement, the pivotally mounted assembly having a plurality of apertureseach of which is located to receive the pilot pin when the assembly isin an angular position in which an aperture in a spray mask carried bythe assembly is substantially aligned with the corresponding aligningpin carried by the work holder.

2. A multiple spray painting fixture according to claim 1 that comprisesa drive for slidably moving the pilot pin, and a separate drive forslidably moving the work holder to engage the aligning pin with thecorresponding aperture in a spray mask after the pilot pin has beenengaged with an aperture in the pivotally mounted assembly.

3. A multiple spray painting fixture according to claim 2 wherein thepivotally mounted assembly is mounted on a horizontal axis and the workholder is slidable vertically.

4. A multiple spray painting fixture according to claim 3 wherein thepivotally mounted assembly comprises a pair of side members carryingmountings for supporting a plurality of horizontally extending spraymasks to permit each of the masks selectively to be brought to aposition vertically above the work holder.

5. A multiple spray painting fixture according to claim 4 wherein theapertures for receiving the pilot pin are located in one of the sidemembers, and the pilot pin is slidable horizontally.

6. A multiple spray painting fixture according to claim 1 wherein thepivotally mounted assembly is mounted on a horizontal axis and the workholder is slidable vertically.

7. A multiple spray painting fixture according to claim 6 wherein thepivotally mounted assembly comprises a pair of side members carryingmountings for supporting a plurality of horizontally extending spraymasks to permit each of the masks selectively to be brought to aposition vertically above the work holder.

8. A multiple spray painting fixture according to claim 7 wherein theapertures for receiving the pilot pin are located in one of the sidemembers, and the pilot pin is slidable horizontally.

9. A multiple spray painting fixture according to claim 7 whereinapertures for receiving a pilot pin are located in both side members,and two horizontally slidable pilot pins are provided for engaging suchapertures.

UNITED STATES PATENTS References Cited 2,475,434 7/1949 Moss 1l8503 XR2,969,296 1/1961 \Valsh 1l738 3,117,025 1/1964 Learn et al. 118504 XR3,205,855 9/1965 Ault ll8301 XR 3,207,126 9/1965 Byron 1l8504 XR3,238,917 3/1966 Burns 118-38 XR 3,241,519 3/1966 Lloyd 1l849 3,302,6092/1967 Walker et al. 101-50 XR CHARLES A. WILLMUTH, Primary Examiner.

R. I. SMITH, Assistant Examiner.

1. A MULTIPLE SPRAY PAINTING FIXTURE COMPRISING A BASE, AN ASSEMBLYWHICH IS PIVOTALLY MOUNTED ON THE BASE AND WHICH CARRIES A PLURALITY OFMOUNTINGS FOR SUPPORTING A PLURALITY OF SPRAY MASKS IN POSITIONS THATARE ANGULARLY DISPLACED FROM ONE ANOTHER, A WORK HOLDER WHICH ISSLIDABLY MOUNTED ON THE BASE AND WHICH CARRIES AN ALIGNING PIN EXTENDINGIN THE DIRECTION OF THE SLIDING MOVEMENT OF THE WORK HOLDER FOR ENGAGINGAN ALIGNING APERTURE IN A SPRAY MASK CARRIED BY THE PIVOTALLY MOUNTEDASSEMBLY, IN ORDER TO ALIGN THE MASK WITH WORK WHICH IS TO BE SPRAYPAINTED THROUGH THE MASK AND WHICH IS HELD ON THE WORK